This is an improved version of a commercial scraper-burnishing jig that’s commonly marketed to luthiers. It makes it easy to form consistent cutting burrs, whether the scraper is square or curved, without the skill and muscle memory you need to use a standard burnishing rod successfully.

At its angled end, my jig is the same as the commercial version. But I added a 90° position at the other end, which lets me use the same tool to first draw the burr upward, an integral part of the scraper sharpening process. In fact, I can renew the same burr 10 or more times with this jig—drawing it upward and then curling it again—before I need to file and hone the edge of the scraper square again and form a new burr.

Step one: Draw burr away from scraper

The jig is simply a short wood handle that holds a 1/4-in.-dia. carbide router bit at two angles, with the shank of the bit acting as the burnishing rod. The angled end has a narrow slot that fits onto the edge of the scraper, helping you keep the handle level and the rod at 10°. I cut this slot with a backsaw, but a bandsaw will also work.

The other part of the jig is a flat piece of 2×4 lumber with a straight edge, where the scraper is held with hand pressure as you burnish it. This is much faster than clamping it in a vise.

Step two: Roll burr over

Before you use the tool each time, put a little oil on the bit shank. Whether you are forming a new burr or re-turning an existing one, the steps are the same. When the burrs become jagged, leaving little stripes on the wood, it’s time to refresh the edges of the scraper entirely, by filing them square again and honing them smooth, so you can draw and turn new burrs. If you want cutting burrs that are more or less aggressive, make a second jig with 5° and 15° holes.

—LARRY MATTHEWS, Upper Darby, Pa.

Illustrations by Dan Thornton
From Fine Woodworking issue #308